VarioProp Hub & Blade Systems give you 2, 3, 4and 5-blade configurations with an ingenious system for adjusting blade pitch in the hub. HUB 6A only weighs 5 grams and allows adjustment from 2.5 inches to 6 inches of pitch. The 6A HUB comes in variations to fit 2.3mm, 3.2mm, and 4.0mm motor/gearbox shafts.
The "Speed" blades for 6A-sized hubs are particularly intended for faster models using direct-drive motors like Hacker B20 18L and B40 S series, Mega 16 Series, UltraFly A30 Direct, and so on. Depending on motor and gear ratio, the "speed" props may be the best solution for a geared system, too, if the target rpm is high.
The Scale blades can also be used either direct-drive or geared.